Don't buy a cheap scope- I have lots of them I will sell you -
They work fine but all have some little nitnoid to deal with... its like they seem to be wearing wool instead of silk.
Little things... like the wrong reticle for the use, touchy AO adjustments, mil-dot + moa turrets (common), tight eye-box requires precise cheek point, blurry edge spots, non-repeatable or mushy turret clicks,not-illuminated, 1"tube, heavy... etc, etc
you don't have to buy into the Night-force price range to get good quality but your best 'value' comes in the mid-range $400-$800 area. Primarily Look for good glass and repeatable adjustments with positive clicks... and a bulletproof warranty.
Once you read the various specs and reviews and decide on a few models- go down to a couple big box stores and look thru the glass- try to find a long distance view in natural light (out of their fluorescent crap) and then somewhere in lower light like their back stock room... or better yet someone with one you can try out.
About a year ago I was looking for a LR scope and the new Vortex StrikeEagle 6-24 had all the right specs...for about $500... it was (is) a lower priced version of their PST (I) which sold for 900 on the street. I couldn't find one anywhere and the front focal plane PST went on fire sale for about $600... so I got one of those like right now! about 2 weeks later Sportsman's got a StrikeEagle in stock so I was able to compare the two and I could have been happy with the cheaper model, although it is a Chinese product so I don't know how it would hold up over time and recoil, but Vortex has a good warranty. I am very happy with my PST. I have 4 or 5 other Vortex products and like them all. I discovered the reason for the fire sale was the new PST-II was coming out so everyone was selling off their stock.
Other good brands with some lower price point offerings include Burris (made in USA), Nikon, PA, SWFA (? the swampfox referred to above?), then you move up to Leupold, Meopta, Minox in the higher side of mid-range